static object GetDependency(CommandService commandService, ConstructorInfo ctor, IServiceProvider provider, Type serviceType)
{
if (serviceType == typeof(IServiceProvider) || serviceType == provider.GetType())
{
return(provider);
}
if (serviceType == typeof(CommandService) || serviceType == commandService.GetType())
{
return(commandService);
}
var service = provider.GetService(serviceType);
if (service == null)
{
throw new InvalidOperationException($"Failed to instantiate {ctor.DeclaringType}, dependency of type {serviceType} was not found.");
}
return(service);
}
public static Func <IServiceProvider, T> CreateProviderConstructor <T>(CommandService commandService, Type type)
{
var constructors = type.GetConstructors(BindingFlags.Public | BindingFlags.Instance);
if (constructors.Length == 0)
{
throw new InvalidOperationException($"{type} has no public non-static constructors.");
}
if (constructors.Length > 1)
{
throw new InvalidOperationException($"{type} has multiple public constructors.");
}
object GetDependency(ConstructorInfo ctor, IServiceProvider provider, Type serviceType)
{
if (serviceType == typeof(IServiceProvider) || serviceType == provider.GetType())
{
return(provider);
}
if (serviceType == typeof(CommandService) || serviceType == typeof(ICommandService) || serviceType == commandService.GetType())
{
return(commandService);
}
var service = provider.GetService(serviceType);
if (service != null)
{
return(service);
}
throw new InvalidOperationException($"Failed to instantiate {ctor.DeclaringType}, dependency of type {serviceType} was not found.");
}
var constructor = constructors[0];
var parameters = constructor.GetParameters();
var arguments = new object[parameters.Length];
var propertiesToInject = new List <PropertyInfo>();
do
{
var properties = type.GetProperties(BindingFlags.Public | BindingFlags.Instance);
for (var i = 0; i < properties.Length; i++)
{
var property = properties[i];
if (property.SetMethod != null && !property.SetMethod.IsStatic && property.SetMethod.IsPublic &&
property.GetCustomAttribute <DoNotInjectAttribute>() == null)
{
propertiesToInject.Add(property);
}
}
type = type.BaseType.GetTypeInfo();
}while (type != typeof(object));
return((provider) =>
{
for (var i = 0; i < parameters.Length; i++)
{
arguments[i] = GetDependency(constructor, provider, parameters[i].ParameterType);
}
T instance;
try
{
instance = (T)constructor.Invoke(arguments);
}
catch (Exception ex)
{
throw new InvalidOperationException($"Failed to instantiate {constructor.DeclaringType}. See the inner exception for more details.", ex);
}
for (var i = 0; i < propertiesToInject.Count; i++)
{
var property = propertiesToInject[i];
property.SetValue(instance, GetDependency(constructor, provider, property.PropertyType));
}
return instance;
});
}